Breast cancer affects approximately 1 in 8 women in the United States and the incidence of breast cancer throughout the world is increasing. Breast cancer currently accounts for 28% of all new cancers diagnosed in women, with almost 40,000 deaths caused by breast cancer each year. The most commonly applied modality for breast cancer screening is X-ray mammography. However, its use of ionizing radiation limits the frequency with which this modality can be employed. Furthermore, mammography has been shown to be less reliable for young women and further, it causes patient discomfort. In addition, mammography suffers from a relatively high false positive rate. Magnetic resonance imaging (MRI) is a powerful tool to monitor women at a high-risk for breast cancer, but its high cost and variable specificity hinders its use as a general screening modality. Ultrasound imaging can be used as a second-line diagnostic tool to differentiate masses detected by X-ray mammography, but operator variability and low specificity make it unsuitable for front-line screening.